An element has the following natural abundances and isotopic masses: 90.92% abundance with 19.99 amu, 0.26% abundance with 20.99 amu, and 8.82% abudance with 21.99 amu. calculate the average atomic mass of this elements.

The average atomic mass of element Z is 20.169 amu.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

.....(1)

Mass of isotope 1 = 19.99 amu

Percentage abundance of isotope 1 = 90.92 %

Fractional abundance of isotope 1 = 0.9092

Mass of isotope 2 = 20.99 amu

Percentage abundance of isotope 2 = 0.26 %

Fractional abundance of isotope 2 = 0.0026

Mass of isotope 3 = 21.99 amu

Percentage abundance of isotope 3 = 8.82 %

Fractional abundance of isotope 3 = 0.0882

Putting values in equation 1, we get:

Hence, the average atomic mass of element Z is 20.169 amu.

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.